Cells And Tissue Organisation

Question 1

What is the plasma membrane?

Answer 1

Outer layer of cell, enclosed cytosol within, phospholipid bilayer with sugars and proteins embedded within, controls exit and entry of substances in and out of cell,

Question 2

What is the nucleus?

Answer 2

Largest organelle, surrounded by nuclear envelope, contains DNA in form of chromosomes, contains the nucleolus (involved in synthesis of ribosomes)

Skeletal muscles= multinucleated
Red blood cells= anuclear

Question 3

What is the cytoskeleton?

Answer 3

Network of protein fibres that give cell shape and allow it to move, composed of microfilaments (provise structural support and allow contractions), microtubules (larger fibres allowing movement too), centrosome (directs organisation of micortubules, pair of centrioles- important in cell division) and cell extensions (projections of plasma membrane important for movement)

Question 4

Mitochondria

Answer 4

Powerhouse of cell, produce energy through aerobic respiration, double-walled with cristae

Question 5

Endoplasmic reticulum

Answer 5

2 types: smooth (responsible for synthesising lipids and hormones and drug detoxification) and rough (studded with ribosomes, export proteins from cell and responsible for protein synthesis)

Question 6

Ribosomes

Answer 6

Small granules made up of RNA and protein, found in cytoplasm and on RER

Question 7

Golgi apparatus

Answer 7

Stack of membrane-bound sacs (cisternae) important for export of proteins from cell, produces lysosomes

Question 8

Lysosomes

Answer 8

Spherical vessels responsible for degredation of cellular waste

Question 9

Cytosol

Answer 9

Watery fluid housing organelles (cytoplasm= cytosol + organelles not incl. nucleus)

Question 10

4 types of tissue

Answer 10

Epithelial (lines surfaces of body cavities, role in transport, diffusion and secretion)
Muscle (generates movement through contraction)
Nervous (communication between CNS and rest of body)
Connective (supportive tissue, structural, insulator and protective role)

Question 11

Parenchymal cell

Answer 11

Main function of tissue

Question 12

Supporting cell

Answer 12

Provides structural support for cell

Question 13

Types of epithelial tissue

Answer 13

Simple:

• Squamous (lines heart, blood vessels, lymph vessels, lung alveoli)
• Cuboidal (kidney tubules and glands)
• Columnar (stomach, small intestine, trachea, fallopian tubes, can be ciliated)
• pseudostratified (columnar ciliated found in respiratory tract)

Stratified:

• squamous (keratinised- dry surfaces, and non-keratinised)
• transistional (pear- shaped cells only found in urinary tract)

Question 14

Types of connective tissue

Answer 14

Loose (areolar)
Adipose
Reticular
Dense
Cartilage
Bone

Question 15

Glands

Answer 15

Epithelia that secrete and store products such as hormones

Question 16

Goblet cells

Answer 16

Unicellular gland

Question 17

Types of exocrine gland

Answer 17

• Merocrine
• Apocrine
• Holocrine

Question 18

Endocrine gland

Answer 18

Ductuless, so secrete products directly into bloodstream

Question 19

Exocrine gland

Answer 19

Secrete products through duct into epithelium

Question 20

Where does connective tissue develop?

Answer 20

Embryonic mesenchyme

Question 21

What is the ECM made up of?

Answer 21

Extracellular fibres (collagen, elastic fibres and reticular fibres) with ground substance (proteoglycan molecules) filling in gaps

Question 22

Proteoglycans

Answer 22

Highly hydrated molecules allowing compressive strength

Question 23

Junction types

Answer 23

Tight
Gap
Desmosome